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Core Concepts

This document explains core concepts found within the ePay Payment System.

CIT vs. MIT Transactions​

Customer-Initiated Transactions (CIT) and Merchant-Initiated Transactions (MIT) are two types of payment transactions that differ based on who triggers them.

  • CIT: A Customer-Initiated Transaction is initiated by the customer at the time of purchase, such as when a cardholder manually enters payment details or approves a payment. CIT is commonly used for one-time purchases or to establish a subscription.

  • MIT: A Merchant-Initiated Transaction is triggered by the merchant without direct involvement from the customer at the time of payment. These are typically used for recurring payments, like subscriptions, or follow-up charges in pay-as-you-go services. MIT can only be used after a successful CIT, establishing the payment relationship.

When to use them:

  • Use CIT for initial payments or when the customer is directly authorizing a transaction.
  • Use MIT for recurring or automatic payments once consent has been established through a prior CIT.

Sessions​

A Session is the starting point for initiating payments. It represents the creation of a payment intention. From a single session, multiple payment attempts can be made by the cardholder.

Each session can have either zero or one successful transaction and may have multiple failed transactions associated with it. For instance, a user may enter their card details and get rejected due to an invalid expiration date. After correcting their information, they can try again within the same session. In this case, the session would include two transaction attempts: one successful and one failed.

States​

  • PENDING: The initial state of a session, indicating that it is waiting for payment method details, usually when the cardholder is entering their card information. At this stage, no payment attempt has started.
  • PROCESSING: The session transitions to this state once a payment attempt is being processed. A session can only have one transaction being processed at any given time.
  • COMPLETED: If the transaction is authorized successfully, the session state updates to COMPLETED, indicating that the session now contains a successful transaction. No further payment attempts can be made.
  • EXPIRED: If the session times out without a successful transaction, the state is updated to EXPIRED, preventing any new payment attempts.

If a transaction fails during the PROCESSING state, the session reverts back to PENDING, allowing for another payment attempt.

Transactions​

A Transaction represents a specific payment attempt. Cit transactions are always tied to a session, MIT transactions have no session. It stores all processing details and logs, which help merchants understand the payment process.

Each transaction has a corresponding event log, offering merchants detailed insights into each stage of the transaction. This transaction log is accessible in the ePay backoffice.

States​

  • PENDING: The transaction is waiting for processing to begin.
  • PROCESSING: The transaction is actively being processed or awaiting external actions, such as 3D Secure (3DS) authentication.
  • SUCCESS: The transaction has been successfully processed.
  • FAILED: If a transaction fails, a new payment attempt can be made immediately by the cardholder.

Subscriptions​

A Subscription represents the agreement a customer has made with a merchant to allow automatic withdrawals from their account. A subscription does not have to follow a regular schedule, such as monthly payments. Subscriptions can be either scheduled or unscheduled.

Unscheduled subscriptions refer to pay-as-you-go services, like parking or bike rentals, where charges occur based on usage. Scheduled subscriptions refer to recurring charges, such as a monthly fee for a streaming service.

  • Unscheduled subscriptions might require additional approval from your payment processor.

A subscription is always initiated by an initial successful Customer-Initiated Transaction (CIT).

States​

  • PENDING: The subscription is awaiting an initial successful CIT transaction.
  • ACTIVE: The subscription is active and can be used for subsequent Merchant-Initiated Transaction (MIT) charges.
  • INVALID: The initial CIT transaction attempts failed, and the subscription could not be established.
  • DISABLED: The subscription has been disabled by either the customer or the merchant, and no further charges are possible.

Processing pipeline​

Each payment method has its own processing pipeline, which consists of a series of actions that are executed during the payment process. The results of each action can be viewed in the transaction log.

Many actions are handled entirely within the ePay system without external involvement. However, some actions require interaction with the cardholder's device, such as redirecting them to complete additional steps.

To support payment methods beyond standard card payments, merchants must ensure that their systems accommodate the necessary actions for those payment methods.

The most common client-side event triggered by these actions is the redirectClient event.

Operations​

Transaction Operations refer to the individual actions that can be performed on a transaction once it has been processed. These operations are critical for managing and adjusting payments after their initial processing. The most common transaction operations are void, capture, and refund, each serving a specific purpose in the lifecycle of a card payment.

Authorization​

An Authorization is the initial step in the payment process where the payment method (typically a credit or debit card) is verified to ensure the cardholder has sufficient funds or credit to complete the purchase. This operation places a hold on the cardholder's funds for the transaction amount but does not immediately transfer the funds to the merchant.

If the merchant does not capture the transaction within a specific timeframe (which varies by payment processor and card issuer), the authorization will expire, and the hold on the funds will be lifted, making the amount available to the cardholder again.

Void​

A Void operation is used to cancel a transaction that has been authorized but not yet captured. This action prevents the transaction from being completed and reverses the authorization, ensuring that the cardholder is not charged. Voids are typically used when the merchant wishes to cancel the order before the funds are captured. A void can only be performed before the transaction has been captured, a refund is required instead.

Capture​

Capture is the process of finalizing a transaction that has been previously authorized. This operation confirms that the merchant is ready to receive the funds, and it triggers the transfer of money from the cardholder to the merchant. In some cases, authorization and capture occur simultaneously (as in most online purchases), but for others, such as certain types of services or pre-orders, the capture is done separately from the authorization. Once a transaction is captured the funds are settled to the merchant’s account.

Refund​

A Refund is used to return funds to the cardholder after a transaction has been successfully captured. This operation is commonly used when a customer returns a product or cancels a service after the payment has been processed. Once a refund is processed, the appropriate amount will be credited back to the cardholder's account.

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ePay supports both full and partial operations with regard to the amount captured, voided or refunded.